Two boys, Ellis and his best friend Neckbone, find a mysterious man named Mud hiding out on a deserted island in the Mississippi. Mud tells the boys fantastic stories about his life, including how he killed a man in Texas and vengeful bounty hunters are coming to get him. He says he is planning to meet and escape with the love of his life, Juniper. The boys agree to help him, but it isn't long until their small town is besieged by bounty hunters out...
Five years after the Civil War, Captain Kidd moves from town to town as a storyteller. In Texas, he crosses paths with Johanna, a ten-year-old taken in by the Kiowa people six years earlier. She is being returned to her biological aunt and uncle against her will. Kidd agrees to deliver the child where the law says she belongs. As they travel hundreds of miles, the two will face tremendous challenges of both human and natural forces as they search...